CN103717683A - Water-proof coating system for reflecting solar radiation and water-borne coating for forming decorative and reflective layer in coating system - Google Patents

Abstract

A waterproof coating system for reflecting solar radiation comprising, optionally, a base layer on a substrate and a reinforcing layer on the base layer; a white reflective waterproof layer on the substrate or on the reinforcing layer; and the white A decorative reflective layer on the reflective waterproof layer; wherein the decorative reflective layer includes colored infrared reflective pigments. Aqueous paint for forming a decorative reflective layer in a coating system comprising an acrylic polymer, a colored infrared reflective pigment and a UV crosslinker. The coating system can efficiently reflect solar radiation and effectively prevent water penetration, has strong pollution resistance and good weather resistance; has strong adhesion to various substrates; and also provides multiple colors for selection. The water-based paint can be applied conveniently and is environmentally friendly.

Description

Water-repellent coating system for reflecting solar radiation and water-based paint for forming a decorative reflective layer in the coating system

technical field

The present invention relates to a waterproof coating system for reflecting solar radiation and to an aqueous paint for forming a decorative reflective layer in said coating system, said aqueous paint comprising an acrylic polymer, a colored infrared reflective pigment and a UV crosslinking agent.

Background technique

The solar radiation reaching the earth's surface provides the necessary conditions for human existence and daily life, and at the same time it inevitably causes an increase in the temperature inside buildings such as houses, offices, and factories because their outer surfaces absorb heat from the solar radiation. To reduce the internal temperature of the building,

Cooling equipment such as showers, air conditioning and ventilation is required and consumes a lot of energy.

Applying coatings - which are effective at reflecting solar radiation - to the exterior surfaces of buildings such as houses, offices and factories is an important way to reduce their internal temperature. Obviously, the more reflective the coating is to solar radiation, the more effective it is at reducing the internal temperature of the building, which further extends the useful life of the building considerably.

U.S. Patent No. 5,434,009 discloses a roof laminate comprising: a first layer for forming an asphalt base layer of the laminate; at least one second layer bonded to the first layer; the second layer comprising an acrylic polymer and a crosslinking-promoting metal complex within the acrylic polymer in an amount sufficient to form a continuous film when applied to the base asphalt layer; and a third layer bonded to the second layer, the third layer The layer is formed from an acrylic polymer and includes a UV blocking agent.

European Patent Application EP1160299A1 discloses an improved exterior elastomeric coating composition comprising an organic binder with a Tg of less than -20°C, and at least one inorganic additive, wherein the improvement comprises adding at least a portion of the The at least one inorganic additive is replaced by a solid particulate organic polymer with a Tg greater than 70°C.

Chinese patent application CN101319121A discloses a multi-functional, high-efficiency and heat-insulating coating comprising 16 to 20 wt% rutile titanium dioxide, 3 to 5 wt% infrared reflective powder and 35 to 40 wt% elastic acrylic emulsion.

Chinese patent application CN101343453A discloses a water-based, elastic, heat-insulating and energy-saving coating, which includes 200 to 250 parts by weight of elastic emulsion, 20 to 35 parts by weight of far-infrared reflective powder and 40 to 60 parts by weight of titanium dioxide. In the process of applying the water-based, elastic, heat-insulating and energy-saving paint to the wall, the primer is applied first, then the water-based, elastic, heat-insulating and energy-saving paint is applied 2 or 3 times, and finally the clear varnish.

US patent application US2005261407A1 discloses a top coating composition with high energy efficiency, reflectivity and durability, comprising: a mixture of a polymer binder, a polymer carrier and an effective amount of pigments, the coating composition is for low A coating capable of providing an initial energy efficiency of greater than or equal to 0.65 for pitched roofs, or a coating with an initial energy efficiency of greater than or equal to 0.25 for steeply sloped roofs; wherein the composition is implanted (in- plant) application.

US patent application US2007054129A1 discloses a roofing membrane with a high degree of solar reflectance comprising: a bitumen base sheet; a tie layer containing reinforcing material; and a solar reflective upper layer.

The above-mentioned existing products cannot simultaneously reflect solar radiation and effectively prevent water infiltration, especially cannot effectively prevent water infiltration for a long time, and in terms of its color, the amount of white exceeds other colors. Therefore, it cannot effectively meet the needs of consumers.

Contents of the invention

In view of the above-mentioned prior art, the inventors have conducted extensive and in-depth research in the technical field of waterproof coatings for reflecting solar radiation, aiming to obtain a coating or coating that can efficiently reflect solar radiation and effectively prevent water penetration system. It has now been found that the above objects can be achieved by a coating system comprising a white reflective waterproof layer and a decorative reflective layer on the reflective waterproof layer, wherein the decorative reflective layer comprises colored infrared reflective pigments . The inventors of the present invention have completed the present invention on the basis of the above findings.

The present invention aims at providing a waterproof coating system for reflecting solar radiation.

The present invention also aims to provide an aqueous coating for forming a decorative reflective layer in a coating system.

In one aspect, the present invention provides a waterproof coating system for reflecting solar radiation, said coating system comprising:

optionally a base layer on the substrate and a reinforcement layer on the base layer;

a white reflective waterproofing layer on said substrate or reinforcing layer; and

a decorative reflective layer on the white reflective waterproof layer;

Wherein the decorative reflective layer contains colored infrared reflective pigments.

In another aspect, the present invention provides an aqueous coating for forming a decorative reflective layer in the coating system, the aqueous coating comprising:

Acrylic polymer;

colored infrared reflective pigments; and

UV crosslinking agent.

The coating system of the present invention is highly reflective to solar radiation and effectively waterproof; has strong stain resistance and good weather resistance, thus preventing the high reflectivity of the coating system to solar radiation from decreasing significantly over time; Has strong adhesion to a wide variety of substrates, as a result of which no primer is required during its application; establishes a good balance of tensile strength and elongation at break between the white reflective waterproofing layer and the decorative reflective layer; also Available in a variety of colors to choose from. The water-based paint used to form the coating system can be applied conveniently and is environmentally friendly.

These and other objects, features and advantages of the invention will become apparent to those skilled in the art upon consideration of the invention as a whole.

Description of drawings

Figure 1 shows a coating system according to one embodiment of the invention.

Figure 2 shows a coating system according to another embodiment of the invention.

Specific embodiments of the invention

According to one embodiment of the present invention, a waterproof coating system for reflecting solar radiation comprises: a white reflective waterproof layer on a substrate; and a decorative reflective layer on the white reflective waterproof layer; wherein the decorative reflective layer contains colored infrared rays reflective paint. The coating system is suitable, for example, for seamless areas of roofs.

According to another embodiment of the present invention, a waterproof coating system for reflecting solar radiation comprises: a base layer on a substrate; a reinforcement layer on the base layer; a white reflective waterproof layer on the reinforcement layer; and a white reflective waterproof layer on the white reflective waterproof layer. A decorative reflective layer; wherein the decorative reflective layer contains colored infrared reflective pigments. The coating system is suitable, for example, for joint areas of roofs, or for other substrates whose mechanical strength is insufficient and which need to be reinforced.

FIG. 1 schematically shows a coating system 10 of the present invention for a seamless area of a roof, which includes a white reflective waterproof layer 12 on a substrate 11 ; and a decorative reflective layer 13 on the white reflective waterproof layer 12 .

Figure 2 schematically illustrates a coating system 20 of the present invention for a roof seam 26 comprising a base layer 22 on a substrate 21; a reinforcement layer 23 on the base layer 22; a white reflective waterproof layer 24 on the reinforcement layer 23; and The decorative reflective layer 25 on the white reflective waterproof layer 24.

By comparing Figure 1 and Figure 2, it can be seen that, according to their different application environments, both the base layer on the substrate and the reinforcing layer on the base layer are optional.

The coating system of the invention is suitable for a wide variety of substrates, such as metal substrates, colored steel sheets, concrete, asphalt substrates or PVC substrates.

The optional base layer in the coating system of the present invention can be any suitable base layer that has good adhesion to the substrate and is known to those skilled in the art. For example, it may be formed from polyester paint or polyurethane paint. For ease of application, the base layer is made of the same material as the white reflective waterproof layer. For example, in the case where the white reflective waterproof layer is formed of an aqueous paint containing an acrylic polymer and a white infrared reflective pigment as proposed below, the base layer is also formed of the aqueous paint. In this case, from the viewpoint of cost saving, the base layer may also be formed of the water-based paint that does not contain white infrared reflective pigments, especially titanium dioxide.

The optional reinforcing layer in the coating system according to the invention is used to increase the mechanical strength of, for example, roof seams, which are preferably nonwovens of fibers. The fibers may be, for example, natural fibers such as wood and cotton; fibers of synthetic materials such as polyester, nylon, polypropylene, polyvinylidene fluoride, ethylene/tetrafluoroethylene copolymer, polyethylene terephthalate , polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly(meth)acrylate, polyether ketone; fibers of inorganic materials such as glass fibers or metal fibers ; or a combination thereof. The reinforcing layer is preferably a non-woven fabric of synthetic fibers, glass fibers or combinations thereof, more preferably a non-woven fabric of polyester fibers or glass fibers. Before the base layer is fully cured, a non-woven fabric of fibers is laid on the base layer to form the reinforcing layer.

In the coating system of the present invention, the white reflective waterproof layer is directly on the substrate without using the base layer and the reinforcing layer; in the case of using the base layer and the reinforcing layer, the white reflective waterproof layer is located on the reinforcing layer.

The white reflective waterproof layer in the coating system of the invention plays an important role in preventing the penetration of water such as rainwater, and at the same time it can effectively reflect solar radiation, especially infrared radiation. For this purpose, the white reflective water-repellent layer in the coating system of the invention comprises white infrared reflective pigments. The white infrared reflective pigment is preferably titanium dioxide, zinc oxide, zinc sulfide or a mixture thereof, more preferably rutile titanium dioxide. In the white reflective waterproof layer, the white infrared reflective pigment is 1 to 50% by weight, preferably 2 to 20% by weight, based on the white reflective waterproof layer.

The white reflective waterproof layer in the coating system of the present invention is formed by a paint containing an acrylic polymer and a white infrared reflective pigment, preferably by a water-based paint containing an acrylic polymer and a white infrared reflective pigment.

Acrylic polymers can be, for example, acrylic homopolymers or copolymers or mixtures thereof, such as homopolymers of acrylic acid, acrylates, methacrylic acid or methacrylates; or acrylate/acrylate copolymers, methacrylic acid ester/methacrylate copolymers; or copolymers formed of two or more of acrylic acid, acrylate esters, methacrylic acid, methacrylate esters, and styrene; or mixtures thereof. The acrylic polymer is preferably acrylate/acrylate copolymer, methacrylate/methacrylate copolymer, acrylate/styrene copolymer, methacrylate/styrene copolymer, acrylate/methacrylate Ester/styrene copolymers or mixtures thereof. The acrylic polymer is advantageously C1-8 alkyl acrylate/C1-8 alkyl acrylate copolymer, C1-8 alkyl methacrylate/C1-8 alkyl methacrylate copolymer, C1-8 alkyl acrylate copolymer, 8 Alkyl ester/styrene copolymer, C1-8 Alkyl methacrylate/Styrene copolymer, C1-8 Alkyl acrylate/C1-8 Alkyl methacrylate/Styrene copolymer or mixtures thereof ; Preferably C1-4 alkyl acrylate/C1-4 alkyl acrylate copolymer, C1-4 alkyl methacrylate/C1-4 alkyl methacrylate copolymer, C1-4 alkyl acrylate /styrene copolymer, C1-4 alkyl methacrylate/styrene copolymer, C1-4 alkyl acrylate/C1-4 alkyl methacrylate/styrene copolymer or mixtures thereof. More specifically, the acrylic polymer may be, for example, butyl acrylate/styrene copolymer or butyl acrylate/methyl methacrylate/styrene copolymer.

Acrylic polymers are commercially available and can also be synthesized by conventional methods known to those skilled in the art. It can be used, for example, in the form of polymer solid particles and also in the form of aqueous polymer dispersions in said aqueous coating materials.

Flex SC138ap、405ap、

GS409ap、

S533和

NX3587；购自Dow ChemicalCompany的Maincote^TM PR-71K、PRIMAL^TM EC-1791和Elstine8556；购自Synthomer的Rcvacryl100和Recarcyl245。Specific examples of commercially available aqueous dispersions of acrylic polymers include, but are not limited to, the

Flex SC138ap, 405ap,

GS409ap,

S533 and

NX3587; Maincote ^™ PR-71K, PRIMAL ^™ EC-1791 and Elstine 8556 available from Dow Chemical Company; Rcvacryl 100 and Recarcyl 245 available from Synthomer.

NX3587的混合物用在所述水性涂料中。Preferably, a mixture of two or more acrylic polymers such as PRIMAL ^TM EC-1791 and

A mixture of NX3587 was used in the waterborne paint.

The acrylic polymer is 22.5 to 32.5% by weight based on the total weight of the waterborne coating.

The white infrared reflective pigment is preferably titanium dioxide, zinc oxide, zinc sulfide or mixtures thereof. Titanium dioxide includes rutile-type titanium dioxide and anatase-type titanium dioxide, and is commercially available, or can be prepared by conventional methods known to those skilled in the art. The white infrared reflective pigment is more preferably rutile titanium dioxide.

With regard to pigments, the aqueous paint comprises only white infrared reflective pigments, preferably only titanium dioxide, zinc oxide, zinc sulfide or mixtures thereof, eg only rutile titanium dioxide, since the reflective waterproof layer is white.

The particle size of the white infrared reflective pigment may be, for example, 0.2 to 0.3 μm.

The white infrared reflective pigment is 0.5 to 25% by weight, preferably 1 to 10% by weight, based on the total weight of the water-based paint.

In addition to acrylic polymers and white infrared reflective pigments, the above-mentioned water-based paints may also include the following other components:

Dispers715W和

Wet KL245；Dispersant, such as available from Evonik Tego Chemie GmbH

Dispers715W and

Wet KL245;

Foamex1488；购自BYK Additives&Instrument的

和

；和购自Cognis的

和

Antifoaming agent, such as available from Evonik Tego Chemie GmbH

Foamex 1488; available from BYK Additives & Instruments

and

; and available from Cognis

and

Fillers, such as barium sulfate, calcium carbonate, talc, kaolin, mica powder, aluminum silicate;

Microbicides such as DeuAdd MB-11 and DeuAdd MB-16 from Elementis Specialties; SKANE ^™ M-8 from Dow Chemical Company;

和

购自Evonik Tego Chemie GmbH的

ViscoPlus3030；和Thickeners such as HEC ER5200 and RM-2020 from Dow Chemical Company;

and

from Evonik Tego Chemie GmbH

ViscoPlus3030; and

pH modifiers such as ammonia; AMP-95 available from Dow Chemical Company; NaOH.

The usage amount of the above-mentioned other components in the water-based paint is the conventional usage amount.

The above waterborne coatings are prepared by mixing the acrylic polymer, white infrared reflective pigment, water and other optional ingredients and then grinding; alternatively, by first mixing the acrylic polymer, water and other optional ingredients and milled, and then prepared by mixing the self-milled mixture with a white infrared reflective pigment. During the preparation process, the final pH value of the water-based paint is adjusted to be in the range of 7.5 to 10.5 by controlling the amount of the pH modifier used therein.

The water-based coating can be applied to the substrate or reinforcement layer by methods conventional in the art such as knife coating, roller coating, brushing, spraying; and then cured under ambient conditions by self-crosslinking to obtain a white reflection Waterproof layer.

The white reflective waterproof layer has a dry film thickness of 0.2 to 1.5 mm, preferably 0.4 to 0.6 mm, without using a base layer and a reinforcing layer. In the case where a base layer and a reinforcement layer are used and the base layer is made of the same material as that of the white reflective waterproof layer, the sum of the thicknesses of the dry film of the base layer, the reinforcement layer, and the dry film of the white reflective waterproof layer is 1 to 2 mm.

The tensile strength of the white reflective waterproof layer is 1 to 4 Mpa, and the elongation at break is 100 to 400%.

At the same time, the white reflective waterproof layer formed by the above-mentioned water-based paint has strong adhesion to various substrates, such as generally 300-2000 N/m adhesion, as a result, no primer is required during its application.

The decorative and reflective layer in the coating system according to the invention has a decorative effect, for example the effect of providing a colored coating system such as gray or dark green, while at the same time it can effectively reflect solar radiation, especially infrared radiation. For this purpose, the decorative reflective layer in the coating system of the invention comprises colored infrared-reflecting pigments.

Based on their specific colors, infrared reflective pigments can be divided into white infrared reflective pigments and colored infrared reflective pigments, where colored infrared reflective pigments mean that their color can be any color except white, such as black infrared reflective pigments reflective paint.

Colored infrared reflective pigments are preferably ferrochromium oxide, cobalt aluminum oxide, cobalt chromium aluminum oxide, manganese antimony titanium oxide, iron zinc titanium oxide, iron aluminum titanium oxide, chromium antimony titanium oxide, nickel antimony titanium oxide, cobalt chromium zinc titanium oxide, cobalt nickel zinc titanium oxide, iron chromium zinc titanium oxide, cobalt chromium manganese zinc aluminum oxide or mixtures thereof. For the gray decorative reflective layer, the colored infrared reflective pigment is 2-30% by weight, based on the decorative reflective layer. For the dark green decorative reflective layer, the colored infrared reflective pigment is 2-20% by weight based on the decorative reflective layer.

The decorative reflective layer in the coating system of the present invention is formed from a paint comprising an acrylic polymer, a colored infrared reflective pigment and a UV crosslinker, preferably from a paint comprising an acrylic polymer, a colored infrared reflective pigment and a UV crosslinker. Waterborne paint formation.

For this reason, the present invention also provides the water-based paint for forming the decorative reflective layer in the coating system, the water-based paint comprising:

Acrylic polymer;

colored infrared reflective pigments; and

UV crosslinking agent.

Acrylic polymers may be, for example, acrylic homopolymers or copolymers or mixtures thereof, such as homopolymers of acrylic acid, acrylates, methacrylic acid or methacrylates; or acrylate/acrylate copolymers, methacrylic acid ester/methacrylate copolymers; or copolymers formed of two or more of acrylic acid, acrylate esters, methacrylic acid, methacrylate esters, and styrene; or mixtures thereof. The acrylic polymer is preferably acrylate/acrylate copolymer, methacrylate/methacrylate copolymer, acrylic/styrene copolymer, methacrylate/styrene copolymer, acrylate/methacrylate / styrene copolymers or mixtures thereof.

The acrylic polymer is advantageously C1-8 alkyl acrylate/C1-8 alkyl acrylate copolymer, C1-8 alkyl methacrylate/C1-8 alkyl methacrylate copolymer, C1-8 alkyl acrylate copolymer, 8 Alkyl ester/styrene copolymer, C1-8 Alkyl methacrylate/Styrene copolymer, C1-8 Alkyl acrylate/C1-8 Alkyl methacrylate/Styrene copolymer or mixtures thereof ; Preferably C1-4 alkyl acrylate/C1-4 alkyl acrylate copolymer, C1-4 alkyl methacrylate/C1-4 alkyl methacrylate copolymer, C1-4 alkyl acrylate /styrene copolymer, C1-4 alkyl methacrylate/styrene copolymer, C1-4 alkyl acrylate/C1-4 alkyl methacrylate/styrene copolymer or mixtures thereof. More specifically, the acrylic polymer may be, for example, butyl acrylate/methyl methacrylate/styrene copolymer.

Acrylic polymers are commercially available and can also be synthesized by conventional methods known to those skilled in the art. It can be used, for example, in the form of polymer solid particles and also in the form of aqueous polymer dispersions in said aqueous coating materials.

405ap、409ap、

和

NX3587；购自Dow ChemicalCompany的PRIMAL^TM EC-1791；购自Synthomer的Rcvacryl100。Specific examples of commercially available aqueous dispersions of acrylic polymers include, but are not limited to, the Flex SC138ap,

405ap, 409ap,

and

NX3587; PRIMAL ^™ EC-1791 available from Dow Chemical Company; Rcvacryl 100 available from Synthomer.

和Revacryl100的混合物用于所述水性涂料中。Preferably, a mixture of two or more acrylic polymers such as

A mixture of Revacryl 100 is used in the water-based paint.

The acrylic polymer is 20 to 35% by weight, preferably 22.5 to 32.5% by weight, based on the total weight of the aqueous coating.

EH0408(0095)，购自Shepherd Color Company的Black30C933和Black30C965。Colored infrared reflective pigments are preferably ferrochromium oxide, cobalt aluminum oxide, cobalt chromium aluminum oxide, manganese antimony titanium oxide, iron zinc titanium oxide, iron aluminum titanium oxide, chromium antimony titanium oxide, nickel antimony titanium oxide, cobalt chromium zinc titanium oxide, cobalt nickel zinc titanium oxide, iron chromium zinc titanium oxide, cobalt chromium manganese zinc aluminum oxide or mixtures thereof. For example, a specific example thereof may be available from BASF as

EH0408(0095), available from Shepherd Color Company as Black30C933 and Black30C965.

Depending on the desired color of the decorative reflective layer, the amount of colored infrared-reflective pigments in the aforementioned water-based paints can vary within a relatively wide range. For the gray decorative reflective layer, the amount of the colored infrared reflective pigment in the above water-based paint is 1-15% by weight. For the dark green decorative reflective layer, the amount of the colored infrared reflective pigment in the water-based paint is 1-10% by weight.

In addition to colored IR-reflecting pigments, white IR-reflecting pigments can also be used in the aqueous paint. For example, in the case of a gray decorative reflective layer, the water-based paint comprises titanium dioxide and a black infrared reflective pigment.

For reasons such as pigment color matching and hiding power, in addition to the above-mentioned colored infrared reflective pigments, the water-based paints used to form the decorative reflective layer in the coating system may also contain other pigments such as iron oxide red and iron oxide yellow. According to the different colors required for the decorative reflective layer, the amount of other pigments in the water-based paint can be determined by those skilled in the art.

Any suitable UV crosslinking agent can be used in the water-based paint forming the decorative reflective layer, and the UV crosslinking agent used is preferably benzophenone, benzophenone substituted by C1-3 alkyl or a mixture thereof . Specific examples of benzophenones substituted with C1-3 alkyl include, but are not limited to, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 4-ethyl Benzophenone, 4-propylbenzophenone, 4-methyl-4'-methylbenzophenone, 4-methyl-4'-ethylbenzophenone, 4-ethyl-4 '-Ethylbenzophenone. A specific example of a UV crosslinker used is Esacure TZM available from LambertiSpa, which consists of about 50% benzophenone and about 50% 4-methylbenzophenone. The UV crosslinking agent is 0.1 to 2% by weight, preferably 0.3 to 1.5% by weight, based on the total weight of the aqueous coating.

In addition to acrylic polymers, colored infrared reflective pigments and UV crosslinkers, the above waterborne coatings may also include other components such as:

W和

Wet KL245；其用量为基于水性涂料计的0.2至1重量％；Dispersant, such as available from Evonik Tego Chemie GmbH

W and

Wet KL245; used in an amount of 0.2 to 1% by weight based on the water-based paint;

和

购自Cognis的

和

其用量为基于水性涂料计的0.2至1重量％；Antifoaming agent, such as available from Evonik Tego Chemie GmbH from BYK Additives & Instruments

and

purchased from Cognis

and

It is used in an amount of 0.2 to 1% by weight based on the water-based paint;

Fillers, such as barium sulfate, calcium carbonate, talc, kaolin, mica powder, aluminum silicate; the amount used is 20 to 40% by weight based on the water-based paint;

Microbicides such as DeuAdd MB-11 and DeuAdd MB-16 available from Elementis Specialties; SKANE ^™ M-8 available from Dow Chemical Company; used in an amount of 0.1 to 0.5% by weight based on the waterborne paint;

购自Evonik Tego Chemie GmbH的

其用量为基于水性涂料计的0.2至1.5重量％；和Thickeners such as HEC ER5200 and RM-2020 from Dow Chemical Company;

from Evonik Tego Chemie GmbH

It is used in an amount of 0.2 to 1.5% by weight based on the water-based paint; and

pH modifiers such as ammonia; AMP-95 available from the Dow Chemical Company; NaOH; the amount used depends on the desired final pH of the waterborne coating and is typically 0.1 to 1% by weight based on the waterborne coating.

The above waterborne coatings are prepared by mixing an acrylic polymer, a colored infrared reflective pigment, an optional white infrared reflective pigment, optional other pigments, a UV crosslinker, water and other optional components and then milling or, by first mixing and grinding the acrylic polymer, UV crosslinker, water, and other optional components, and then combining the self-milled mixture with a colored infrared reflective pigment, optionally a white infrared reflective pigment, and Optionally other pigments are mixed and prepared.

The water-based paint can be applied to the white reflective waterproof layer by conventional methods in the art such as knife coating, roller coating, brushing, spraying; and then UV cured under ambient conditions to obtain a decorative reflective layer.

The dry film thickness of the decorative reflective layer is 0.02 to 0.3 mm, preferably 0.08 to 0.1 mm.

The tensile strength of the decorative reflective layer is 1 to 4Mpa, and the elongation at break is 100 to 400%.

At the same time, the decorative reflective layer formed by the above-mentioned water-based paint has strong pollution resistance, and usually shows a pollution resistance below level 2 in the colorimetric method; it has good weather resistance, and can successfully pass 1000 hours of acceleration under a xenon lamp Aging tests were carried out without any significant changes; thus preventing the high reflectivity of the coating system for solar radiation from decreasing significantly over time.

The coating system according to the invention is suitable for roofs and walls of buildings such as houses, offices and factories, especially buildings in regions of high temperature and long rainy seasons.

Example

The present invention will be specifically described with reference to the following examples, but the examples are not intended to limit the scope of the present invention in any way.

The total solar radiation reflectance of the coating system is tested according to GJB2502-1996 (210); the water impermeability of the coating system, the tensile strength and elongation at break of the white reflective waterproof layer and the decorative reflective layer are tested according to GB/T16777-1997 The adhesion of the coating system to the substrate is tested according to GB/T2790-1995; the pollution resistance of the coating system is tested according to GB/T9780; and the weather resistance of the coating system is tested according to GB/T1865-1997.

The particle size of titanium dioxide used in the following Examples and Comparative Examples was 0.2 to 0.3 μm.

Example 1

The formulation of the water-based paint used to form the white reflective waterproof layer in the coating system is shown in Table 1 below, and the pH value of the water-based paint is 9.5.

Table 1 is used to form the water-based paint 1 of white reflective waterproof layer

The formulation of the waterborne paint used to form the gray decorative reflective layer in the coating system is shown in Table 2 below.

Table 2 is used to form the water-based paint 2 of the gray decorative reflective layer

Waterborne Coating 1 was sprayed in an amount of 0.82 kg/ ^m2 onto colored steel panels (coated with polyester) at a temperature of 32°C and a relative humidity of 20% and cured by self-crosslinking under ambient conditions To obtain a white reflective waterproof layer with a dry film thickness of 400 μm; at a temperature of 32° C. and a relative humidity of 20%, the water-based paint 2 is sprayed on the white reflective waterproof layer in an amount of 0.28 kg/m ² , and in the environment UV curing under conditions to obtain a gray decorative reflective layer with a dry film thickness of 100 μm; thus obtaining the coating system 1 of the present invention.

Example 2

The formulation of the water-based paint used to form the white reflective waterproof layer in the coating system is shown in Table 3 below, and the pH value of the water-based paint is 9.5.

Table 3 is used to form the water-based paint 3 of white reflective waterproof layer

The formulation of the waterborne paint used to form the dark green decorative reflective layer in the coating system is shown in Table 4 below.

Table 4 is used to form the water-based paint 4 of dark green decorative reflective layer

^a was purchased from BASF, the same below.

Waterborne Coating 3 was sprayed in an amount of 0.82 kg/ ^m2 onto colored steel panels (coated with polyester) at a temperature of 23°C and a relative humidity of 50% and cured by self-crosslinking under ambient conditions To obtain a white reflective waterproof layer with a dry film thickness of 400 μm; at a temperature of 23° C. and a relative humidity of 50%, the water-based paint 4 is sprayed on the white reflective waterproof layer in an amount of 0.28 kg/m ² , and in the environment UV curing under the same conditions to obtain a dark green decorative reflective layer with a dry film thickness of 100 μm; thereby obtaining the coating system 2 of the present invention.

Example 3

The formulation of the water-based paint used to form the white reflective waterproof layer in the coating system is shown in Table 5 below, and the pH value of the water-based paint is 9.5.

Table 5 is used to form the water-based paint 5 of white reflective waterproof layer

The waterborne paints used to form the dark green decorative reflective layer in the coating system are shown in Table 4 above.

At a temperature of 32°C and a relative humidity of 20%, the aqueous coating 5 was sprayed in an amount of 1 kg/ ^m2 onto colored steel panels (coated with polyester) and cured under ambient conditions by self-crosslinking to A white reflective waterproof layer with a dry film thickness of 500 μm was obtained; at a temperature of 32° C. and a relative humidity of 20%, the water-based paint 4 was sprayed on the white reflective waterproof layer in an amount of 0.56 kg/m ² . Under UV curing to obtain a dark green decorative reflective layer with a dry film thickness of 200 μm; thereby obtaining the coating system 3 of the present invention.

Comparative Example 1

The waterborne coatings used to form the white base coat in the comparative coating system are shown in Table 1 above.

The formulation of the waterborne paint used to form the gray top coat in the comparative coating system is shown in Table 6 below.

Table 6 Aqueous paint 6 for forming gray top coat

^b carbon black, purchased from BASF, the same below.

Waterborne Coating 1 was sprayed in an amount of 0.82 kg/ ^m2 onto colored steel panels (coated with polyester) at a temperature of 32°C and a relative humidity of 20% and cured by self-crosslinking under ambient conditions To obtain a white base coat with a dry film thickness of 400 μm; at a temperature of 32° C. and a relative humidity of 20%, the water-based paint 6 is sprayed on the white base coat in an amount of 0.28 kg/m ² , and the Cure by self-crosslinking under conditions to obtain a gray topcoat with a dry film thickness of 100 μm; thus comparative coating system 1 is obtained.

Comparative Example 2

The waterborne coatings used to form the white basecoat in the comparative coating system are shown in Table 3 above.

The formulation of the waterborne paint used to form the dark green top coat in the comparative coating system is shown in Table 7 below.

Table 7 is used to form the water-based paint 7 of dark green top coat

Waterborne Coating 3 was sprayed in an amount of 0.82 kg/ ^m2 onto colored steel panels (coated with polyester) at a temperature of 23°C and a relative humidity of 50% and cured by self-crosslinking under ambient conditions To obtain a white base coat with a dry film thickness of 400 μm; at a temperature of 23° C. and a relative humidity of 50%, the water-based paint 7 is sprayed onto the white base coat in an amount of 0.28 kg/m ² , and the UV curing under conditions to obtain a dark green topcoat with a dry film thickness of 100 μm; thus a comparative coating system 2 was obtained.

Performance Testing

Coating systems 1-3 and comparative coating systems 1-2 were tested according to the above mentioned standard and the results obtained are shown in Table 8 below.

Claims (24)

1. A waterproof coating system for reflecting solar radiation, said coating system comprising: optionally a base layer on the substrate and a reinforcement layer on the base layer; a white reflective waterproof layer on said substrate or on said reinforcing layer; and a decorative reflective layer on the white reflective waterproof layer; Wherein, the decorative reflective layer contains colored infrared reflective pigments. 2. The coating system of claim 1, wherein the colored infrared reflective pigment is selected from the group consisting of ferrochromium oxide, cobalt aluminum oxide, cobalt chromium aluminum oxide, manganese antimony titanium oxide, iron zinc titanium oxide, iron aluminum Titanium oxide, chromium antimony titanium oxide, nickel antimony titanium oxide, cobalt chromium zinc titanium oxide, cobalt nickel zinc titanium oxide, iron chromium zinc titanium oxide and cobalt chromium manganese zinc aluminum oxide. 3. The coating system of claim 1 or 2, wherein the decorative reflective layer is formed from an aqueous paint comprising an acrylic polymer and a UV crosslinker. 4. The coating system of claim 3, wherein the acrylic polymer is C1-8 alkyl acrylate/C1-8 alkyl acrylate copolymer, C1-8 alkyl methacrylate/methacrylic acid C1-8 alkyl ester copolymer, C1-8 alkyl acrylate/styrene copolymer, C1-8 alkyl methacrylate/styrene copolymer, C1-8 alkyl acrylate/C1- methacrylate 8 Alkyl ester/styrene copolymers or mixtures thereof. 5. The coating system according to claim 3 or 4, wherein the UV crosslinking agent is benzophenone, benzophenone substituted by C1-3 alkyl, or a mixture thereof. 6. The coating system according to any one of claims 3 to 5, wherein the UV crosslinker is 0.1 to 2% by weight, preferably 0.3 to 1.5% by weight, based on the total weight of the aqueous coating. 7. The coating system of any one of claims 1 to 6, wherein the white reflective waterproof layer comprises a white infrared reflective pigment selected from the group consisting of titanium dioxide, zinc oxide and zinc sulphide. 8. The coating system of claim 7, wherein the white reflective waterproof layer comprises rutile titanium dioxide as a white infrared reflective pigment. 9. The coating system according to claim 7 or 8, wherein the white infrared reflective pigment is 1 to 50% by weight, preferably 2 to 20% by weight, based on the white reflective waterproof layer. 10. The coating system of any one of claims 1 to 9, wherein the white reflective waterproof layer is formed from a waterborne paint comprising an acrylic polymer. 11. The coating system of claim 10, wherein the acrylic polymer is C1-8 alkyl acrylate/C1-8 alkyl acrylate copolymer, C1-8 alkyl methacrylate/methacrylic acid C1-8 alkyl ester copolymer, C1-8 alkyl acrylate/styrene copolymer, C1-8 alkyl methacrylate/styrene copolymer, C1-8 alkyl acrylate/C1- methacrylate 8 Alkyl ester/styrene copolymers or mixtures thereof. 12. The coating system according to any one of claims 1 to 11, wherein the decorative reflective layer has a dry film thickness of 0.02 to 0.3 mm, preferably 0.08 to 0.1 mm. 13. The coating system according to any one of claims 1 to 12, wherein the decorative reflective layer has a tensile strength of 1 to 4 MPa and an elongation at break of 100% to 400%. 14. The coating system according to any one of claims 1 to 13, wherein the white reflective waterproof layer has a dry film thickness of 0.2 to 1.5 mm, preferably 0.4 to 0.6 mm. 15. The coating system according to any one of claims 1 to 14, wherein the white reflective waterproof layer has a tensile strength of 1 to 4 MPa and an elongation at break of 100% to 400%. 16. The coating system according to any one of claims 1 to 15, wherein the reinforcing layer is a non-woven fabric of synthetic material fibers, glass fibers or combinations thereof. 17. The coating system of any one of claims 1 to 16, wherein the base layer is made of the same material as the white reflective waterproofing layer. 18. The coating system according to any one of claims 1 to 17, wherein the substrate is a metal substrate, a colored steel sheet, concrete, an asphalt substrate or a PVC substrate. 19. A waterborne paint for forming a decorative reflective layer in a coating system, said waterborne paint comprising: Acrylic polymer; colored infrared reflective pigments; and UV crosslinking agent. 20. The water-based paint of claim 19, wherein the acrylic polymer is C1-8 alkyl acrylate/C1-8 alkyl acrylate copolymer, C1-8 alkyl methacrylate/C1-8 methacrylate Alkyl ester copolymer, C1-8 alkyl acrylate/styrene copolymer, C1-8 alkyl methacrylate/styrene copolymer, C1-8 alkyl acrylate/C1-8 alkyl methacrylate Ester/styrene copolymers or mixtures thereof. 21. The waterborne paint of claim 19 or 20, wherein the acrylic polymer is present in an amount of 20 to 35% by weight, preferably 22.5 to 32.5% by weight, based on the total weight of the waterborne paint. 22. The waterborne coating of any one of claims 19 to 21, wherein the colored infrared reflective pigment is selected from the group consisting of ferrochromium oxide, cobalt aluminum oxide, cobalt chromium aluminum oxide, manganese antimony titanium oxide, iron zinc titanium oxides, iron aluminum titanium oxide, chromium antimony titanium oxide, nickel antimony titanium oxide, cobalt chromium zinc titanium oxide, cobalt nickel zinc titanium oxide, iron chromium zinc titanium oxide and cobalt chromium manganese zinc aluminum oxide. 23. The waterborne coating according to any one of claims 19 to 22, wherein the UV crosslinking agent is benzophenone, benzophenone substituted with C1-3 alkyl, or a mixture thereof. 24. The aqueous coating of any one of claims 19 to 23, wherein the UV crosslinker is present in an amount of 0.1 to 2 wt%, preferably 0.3 to 1.5 wt%, based on the total weight of the aqueous coating.

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